Problem: $\dfrac{9}{6} - \dfrac{3}{8} = {?}$
$ = {\dfrac{9 \times 4}{6 \times 4}} - {\dfrac{3 \times 3}{8 \times 3}} $ $ = {\dfrac{36}{24}} - {\dfrac{9}{24}} $ $ = \dfrac{{36} - {9}}{24} $ $ = \dfrac{27}{24}$